The metabolic syndrome is associated with high-normal urinary albumin excretion and retinopathy in normoalbuminuric type 1 diabetic patients.

Although metabolic syndrome was not extensively studied in type 1 diabetes, higher insulin resistance, the core feature of the syndrome was found to be associated with increased risk of developing microvascular complications. As diabetic nephropathy may progress to advanced lesion before microalbuminuria appears, we investigated the association of the metabolic syndrome and estimated glucose disposal rate (eGDR) with urinary albumin excretion (UAE), retinopathy and neuropathy in normoalbuminuric type 1 diabetic patients. Two hundred and 98 patients (UAE < 30 mg / 24 h at three occasions) were divided according to the IDF metabolic syndrome; eGDR (mg kg(-1) min(-1)) was calculated: 24.31-(12.22 x WHR) - (3.29 x HT) - (0.57 x HbA1c), (WHR = waist-to-hip ratio, HT = hypertension). Patients with (n = 99) compared to those without metabolic syndrome (N = 199) showed higher UAE (15.96 +/- 9.10; 13.48 +/- 8.36 mg /24 h), C-reactive protein (2.39 +/- 4.09;1.12 +/- 2.03 mg/L), prevalence of retinopathy (70.7; 55.27%) and polyneuropathy (80.8; 68.3%), and lower eGDR (5.75 +/- 1.74; 8.96 +/- 1.9), (p > 0.05). In patients with high-normal UAE, retinopathy and polyneuropathy eGDR was significantly lower compared with patients with low-normal UAE, and without retinopathy and polyneuropathy. In multiple regression analysis UAE and retinopathy were associated with diabetes duration (beta = -0.20, beta = -0.62), eGDR (beta = - 0.106; beta = -0.041), metabolic syndrome (beta = 0.49, beta = 0.28), (p > 0.05). In type 1 diabetic patients insulin resistance and IDF defined metabolic syndrome are associated with high-normal UAE, retinopathy and polyneuropathy. The predictive value of the metabolic syndrome for development of microalbuminuria and retinopathy needs to be assessed in further follow-up studies.